西北干旱区柴窝堡湖干涸湖底粉尘潜在扩散特征

A preliminary study on the transport pathways of dust originating from playa of Chaiwopu Lake, arid northwest China

运用HYSPLIT模型,结合美国环境预报中心（NCEP）和大气研究中心（NCAR）2000～2013年的再分析气象资料,对柴窝堡盆地粉尘潜在扩散的时间和空间特征进行了研究.结果表明：柴窝堡湖干涸湖底粉尘潜在扩散范围具有明显的季节分异.春季粉尘潜在扩散范围和密度最大,覆盖我国大部分地区,最远可达朝鲜半岛部分地区,其次是秋季,夏季粉尘潜在扩散以1000m为界表明出明显的高度差异,冬季粉尘潜在扩散范围和密度均是最小的.随高度增加,不同季节气流可能携带粉尘密度均呈降低趋势.受地形影响,粉尘潜在扩散有两个主要通道,100m以下主要向西南方向扩散,而100m以上主要向东南方向扩散.柴窝堡盆地干涸湖底大量的粉尘在气流携带下可以长时间远距离输送,在近源区沉降,严重影响乌鲁木齐及其周边地区,并可能加速天山山区的雪冰消融.

In order to understand the potential dust transport pathways and the spatiotemporally characteristics of dust at different heights, seasonal climatologies of air parcel trajectories from playa of Chaiwopu Lake was created using the Hybrid Single Particle Lagrangian Integrated Trajectory Model （HYSPLIT） coupled with reanalysis meteorological data （2000-2013） from the National Centers for Environmental Prediction （NCEP） and the National Center for Atmospheric Research （NCAR）. The results showed that spring has the largest potential diffusion range at each height, at which dust from Chaiwopu basin can potentially affect most parts of China, and some areas as far away as the Korean peninsula. Dust diffusion in summer has obvious height differentiation around 1000 meter; however that of winter is minimum. Dust diffusion range turned out changing seasonally at different height. Air parcel trajectories densities reduced with the increase of height in four seasons. The potential transport corridors of dust was southeast toward above 100m, while potential transport corridors turned to southwest below 100meter. Under favorable atmospheric conditions, dust originating from Chaiwopu Lake can affect regions many thousands of kilometers in a relatively short period of time. After settlement in the near source region, the dust mainly influences Urumqi and its surrounding areas, importantly accelerates the melting of snow and ice of Tianshan Mountains.